package com.ztt.vxchat.utils;

import cn.hutool.core.io.IORuntimeException;
import cn.hutool.core.io.file.FileReader;
import cn.hutool.json.JSONException;
import cn.hutool.json.JSONObject;
import cn.hutool.json.JSONUtil;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.Formatter;

public class CheckoutUtil {
 
    /**
     * 验证签名
     * @param signature
     * @param timestamp
     * @param nonce
     * @return
     */
    public static boolean checkSignature(String signature, String timestamp, String nonce) {
        String vxConfigPath = ToolsUtil.getNowProjectPath()+"/vx-config.json";


        FileReader fileReader = null;
        try {
            fileReader= new FileReader(vxConfigPath);
        }catch (IORuntimeException e) {
            return false;
        }

        String vxConfig = fileReader.readString();
        JSONObject vxConfigJson = null;
        try {
            vxConfigJson = JSONUtil.parseObj(vxConfig);
        }catch (JSONException e){
            return false;
        }

        String verToken = vxConfigJson.getStr("verToken");



        String[] arr = new String[] { verToken, timestamp, nonce };
         Arrays.sort(arr);// 将token、timestamp、nonce三个参数进行字典序排序
        StringBuilder content = new StringBuilder();
        for (int i = 0; i < arr.length; i++) {
            content.append(arr[i]);
        }
        MessageDigest md = null;
        String tmpStr = null;
 
        try {
            md = MessageDigest.getInstance("SHA-1");
            // 将三个参数字符串拼接成一个字符串进行sha1加密
            byte[] digest = md.digest(content.toString().getBytes());
            tmpStr = byteToHex(digest );
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        // 将sha1加密后的字符串可与signature对比，标识该请求来源于微信
        return tmpStr != null ? tmpStr.equals(signature) : false;
    }
 
    //十六进制字节数组转为字符串
    private static String byteToHex(final byte[] hash) {
        Formatter formatter = new Formatter();
        for (byte b : hash) {
            formatter.format("%02x", b);
        }
        String result = formatter.toString();
        formatter.close();
        return result;
    }
}